Widespread transposon co-option in the Caenorhabditis germline regulatory network.

The movement of selfish DNA elements can lead to widespread genomic alterations with potential to create novel functions. We show that transposon expansions in Caenorhabditis nematodes led to extensive rewiring of germline transcriptional regulation. We find that about one-third of Caenorhabditis elegans germline-specific promoters have been co-opted from two related miniature inverted repeat transposable elements (TEs), CERP2 and CELE2. These promoters are regulated by HIM-17, a THAP domain-containing transcription factor related to a transposase. Expansion of CERP2 occurred before radiation of the Caenorhabditis genus, as did fixation of mutations in HIM-17 through positive selection, whereas CELE2 expanded only in C. elegans. Through comparative analyses in Caenorhabditis briggsae, we find not only evolutionary conservation of most CERP2 co-opted promoters but also a substantial fraction that are species-specific. Our work reveals the emergence and evolutionary conservation of a novel transcriptional network driven by TE co-option with a major impact on regulatory evolution.

DREAM represses distinct targets by cooperating with different THAP domain proteins.

The DREAM (dimerization partner [DP], retinoblastoma [Rb]-like, E2F, and MuvB) complex controls cellular quiescence by repressing cell-cycle and other genes, but its mechanism of action is unclear. Here, we demonstrate that two C. elegans THAP domain proteins, LIN-15B and LIN-36, co-localize with DREAM and function by different mechanisms for repression of distinct sets of targets. LIN-36 represses classical cell-cycle targets by promoting DREAM binding and gene body enrichment of H2A.Z, and we find that DREAM subunit EFL-1/E2F is specific for LIN-36 targets. In contrast, LIN-15B represses germline-specific targets in the soma by facilitating H3K9me2 promoter marking. We further find that LIN-36 and LIN-15B differently regulate DREAM binding. In humans, THAP proteins have been implicated in cell-cycle regulation by poorly understood mechanisms. We propose that THAP domain proteins are key mediators of Rb/DREAM function.

Distinctive regulatory architectures of germline-active and somatic genes in C. elegans.

RNA profiling has provided increasingly detailed knowledge of gene expression patterns, yet the different regulatory architectures that drive them are not well understood. To address this, we profiled and compared transcriptional and regulatory element activities across five tissues of Caenorhabditis elegans, covering ∼90% of cells. We find that the majority of promoters and enhancers have tissue-specific accessibility, and we discover regulatory grammars associated with ubiquitous, germline, and somatic tissue-specific gene expression patterns. In addition, we find that germline-active and soma-specific promoters have distinct features. Germline-active promoters have well-positioned +1 and -1 nucleosomes associated with a periodic 10-bp WW signal (W = A/T). Somatic tissue-specific promoters lack positioned nucleosomes and this signal, have wide nucleosome-depleted regions, and are more enriched for core promoter elements, which largely differ between tissues. We observe the 10-bp periodic WW signal at ubiquitous promoters in other animals, suggesting it is an ancient conserved signal. Our results show fundamental differences in regulatory architectures of germline and somatic tissue-specific genes, uncover regulatory rules for generating diverse gene expression patterns, and provide a tissue-specific resource for future studies.

Comparative Epigenomics Reveals that RNA Polymerase II Pausing and Chromatin Domain Organization Control Nematode piRNA Biogenesis.

Piwi-interacting RNAs (piRNAs) are important for genome regulation across metazoans, but their biogenesis evolves rapidly. In Caenorhabditis elegans, piRNA loci are clustered within two 3-Mb regions on chromosome IV. Each piRNA locus possesses an upstream motif that recruits RNA polymerase II to produce an ∼28 nt primary transcript. We used comparative epigenomics across nematodes to gain insight into the origin, evolution, and mechanism of nematode piRNA biogenesis. We show that the piRNA upstream motif is derived from core promoter elements controlling snRNA transcription. We describe two alternative modes of piRNA organization in nematodes: in C. elegans and closely related nematodes, piRNAs are clustered within repressive H3K27me3 chromatin, while in other species, typified by Pristionchus pacificus, piRNAs are found within introns of active genes. Additionally, we discover that piRNA production depends on sequence signals associated with RNA polymerase II pausing. We show that pausing signals synergize with chromatin to control piRNA transcription.

CD38 as an immunotherapeutic target in multiple myeloma.

INTRODUCTION: Multiple myeloma (MM) is a currently incurable hematologic tumor with heterogeneous clinical behavior and prognosis. During the last years, survival improved due to a better understanding of MM biology and the development of novel drugs, although it still remains unsatisfactory in many cases: new drugs and treatment strategies are needed. CD38 is uniformly expressed at high levels on MM cells and, to a lesser extent, on the surface of normal hematopoietic and non-hematopoietic cells, making this molecule an interesting target for immunotherapeutic approaches. AREAS COVERED: This review discusses the preclinical and clinical experience on different immunotherapeutic agents targeting CD38 in MM. EXPERT OPINION: Monoclonal antibodies (mAbs) targeting CD38 are currently changing the treatment scenario in MM, allowing physicians to reach unprecedented results, especially when anti-CD38 mAbs are used in combination with consolidated MM treatments. Other immunotherapies targeting CD38 - such as conjugated anti-CD38 mAbs, bispecific antibodies stimulating T cells to eliminate CD38+ MM cells, and CD38-specific chimeric antigen receptor T cells - are interesting strategies, currently at earlier developmental stages.

Chromatin accessibility dynamics across C. elegans development and ageing.

An essential step for understanding the transcriptional circuits that control development and physiology is the global identification and characterization of regulatory elements. Here, we present the first map of regulatory elements across the development and ageing of an animal, identifying 42,245 elements accessible in at least one Caenorhabditis elegans stage. Based on nuclear transcription profiles, we define 15,714 protein-coding promoters and 19,231 putative enhancers, and find that both types of element can drive orientation-independent transcription. Additionally, more than 1000 promoters produce transcripts antisense to protein coding genes, suggesting involvement in a widespread regulatory mechanism. We find that the accessibility of most elements changes during development and/or ageing and that patterns of accessibility change are linked to specific developmental or physiological processes. The map and characterization of regulatory elements across C. elegans life provides a platform for understanding how transcription controls development and ageing.

Treatment Intensification With Autologous Stem Cell Transplantation and Lenalidomide Maintenance Improves Survival Outcomes of Patients With Newly Diagnosed Multiple Myeloma in Complete Response.

BACKGROUND: High-dose therapy with autologous stem cell transplantation (HDT-ASCT) and maintenance treatment with novel agents are the best options for patients with newly diagnosed multiple myeloma, increasing the rate of complete response (CR) and prolonging progression-free survival (PFS) and overall survival (OS). Indeed, the achievement of a CR is a predictor of long-term survival among transplant-eligible patients. However, it is unclear whether patients reaching a CR after induction treatment could receive less intense consolidation or avoid maintenance therapy. PATIENTS AND METHODS: We analyzed CR patients treated in 2 phase III trials, GIMEMA-RV-MM-PI-209 and RV-MM-EMN-441, to compare HDT-ASCT with an R-Alk (lenalidomide, alkylator) regimen as consolidation, and lenalidomide (R) maintenance with no maintenance. The primary endpoints were PFS, second PFS (PFS2), and OS from consolidation and maintenance (_m). RESULTS: Overall, the data from 166 patients in CR were analyzed, 95 in the HDT-ASCT group and 71 in the R-Alk group. The CR patients who received HDT-ASCT had a better PFS (hazard ratio [HR], 0.55; P = .01), PFS2 (HR, 0.46; P = .02), and OS (HR, 0.42; P = .03) compared with patients randomized to R-Alk. The survival benefit with HDT-ASCT was confirmed among all the subgroups, according to age, International Staging System (ISS stage, cytogenetic profile, and receipt of maintenance therapy. CR patients who received lenalidomide maintenance had a better PFS_m (4 years: 54% vs. 19%; HR, 0.43; P = .02) compared with those who received no maintenance. However, no difference was observed in terms of PFS2_m (4 years: 72% vs. 58%; HR, 0.83; P = .67) and OS_m (4 years: 79% vs. 72%; HR, 0.82; P = .73) with maintenance therapy. CONCLUSION: Even in CR patients, outcomes were improved by an intensified approach with HDT-ASCT consolidation and lenalidomide-based maintenance therapy.

Maintenance in myeloma patients achieving complete response after upfront therapy: a pooled analysis.

PURPOSE: Maintenance demonstrated to improve survival in newly diagnosed multiple myeloma (NDMM) patients and the achievement of complete response (CR) is a strong predictor of survival. Nevertheless, the role of maintenance according to response after induction/consolidation has not been investigated so far. To evaluate the impact of maintenance according to response, we pooled together and retrospectively analyzed data from 955 NDMM patients enrolled in two trials (GIMEMA-MM-03-05 and RV-MM-PI-209). METHODS: Primary endpoints were progression-free survival (PFS)1, PFS2 and overall survival (OS) of CR patients randomized to maintenance and no maintenance. Secondary endpoints were PFS1, PFS2 and OS in very good partial response/partial response (VGPR/PR) patients. RESULTS: Overall, 213 patients obtained CR after induction/consolidation, 118 received maintenance and 95 no maintenance. In patients achieving CR, maintenance significantly improved PFS1 (HR 0.50, P < 0.001), PFS2 (HR 0.58, P 0.02) and OS (HR 0.51, P 0.02) compared with no maintenance; the advantage was maintained across all the analyzed subgroups according to age, International Staging System (ISS) stage, cytogenetic profile and treatment. Similar features were seen in VGPR/PR patients. CONCLUSION: Maintenance prolonged survival in CR and in VGPR/PR patients. The benefit in CR patients suggests the importance of continuing treatment in patients with chemo-sensitive disease. TRIAL REGISTRATION: The two source studies are registered at ClinicalTrials.gov: identification numbers NCT01063179 and NCT00551928.

Plasma cell leukemia: update on biology and therapy.

Plasma cell leukemia (PCL) is a rare, but very aggressive, plasma cell dyscrasia, representing a distinct clinicopathological entity as compared to multiple myeloma (MM), with peculiar biological and clinical features. A hundred times rarer than MM, the disease course is characterized by short remissions and poor survival. PCL is defined by an increased percentage (>20%) and absolute number (>2 × 109/l) of plasma cells in the peripheral blood. PCL is defined as 'primary' when peripheral plasmacytosis is detected at diagnosis, 'secondary' when leukemization occurs in a patient with preexisting MM. Novel agents have revolutionized the outcomes of MM patients and have been introduced also for the treatment of PCL. Here, we provide an update on biology and treatment options for PCL.

New pharmacotherapy options for multiple myeloma.

INTRODUCTION: Novel agents and the availability of autologous stem-cell transplantation have revolutionized the treatment of patients with multiple myeloma. First-generation novel agents namely thalidomide, lenalidomide, and bortezomib have significantly improved response and survival of patients. Second-generation novel agents such as pomalidomide, carfilzomib, and monoclonal antibodies are being tested both in the newly diagnosed and relapse settings, and results are promising. AREAS COVERED: In this review article, the main results derived from Phase III trials with thalidomide, lenalidomide, and bortezomib for the treatment of myeloma patients, both at diagnosis and at relapse, are summarized. Data about second-generation novel agents such as pomalidomide and carfilzomib are also reported. Newer effective drugs currently under investigation and the promising results with monoclonal antibodies are described. EXPERT OPINION: The availability of new effective drugs has considerably increased the treatment options for myeloma patients. A sequential approach including induction, transplantation (when possible), consolidation, and maintenance is an optimal strategy to achieve disease control and prolong survival. Despite these improvements, the best combination, the optimal sequence, and the proper target of newer drugs need to be defined.

Continuous Therapy Versus Fixed Duration of Therapy in Patients With Newly Diagnosed Multiple Myeloma.

PURPOSE: Continuous therapy (CT) prolongs progression-free survival 1 (PFS1; time from random assignment until the first progression or death), but chemotherapy-resistant relapse may negatively impact overall survival (OS). Progression-free survival 2 (PFS2; time from random assignment until the second progression or death) may represent an additional tool to estimate outcome. This study evaluates the benefit of novel agent-based CT versus fixed duration of therapy (FDT) in patients with newly diagnosed myeloma. METHODS: We included patients enrolled onto three phase III trials that randomly assigned patients to novel agent-based CT versus FDT. Primary analyses were restricted to the intent-to-treat population eligible for CT (patients progression free and alive at 1 year after random assignment). Primary end points were PFS1, PFS2, and OS. All hazard ratios (HRs) and 95% CIs were adjusted for several potential confounders using Cox models. RESULTS: In the pooled analysis of the three trials, 604 patients were randomly assigned to CT and 614 were assigned to FDT. Median follow-up was 52 months. In the intent-to-treat CT population, CT (n = 417), compared with FDT (n = 410), significantly improved PFS1 (median, 32 v 16 months, respectively; HR, 0.47; 95% CI, 0.40 to 0.56; P < .001), PFS2 (median, 55 v 40 months, respectively; HR, 0.61; 95% CI, 0.50 to 0.75; P < .001), and OS (4-year OS, 69% v 60%, respectively; HR, 0.69; 95% CI, 0.54 to 0.88; P = .003). CONCLUSION: In this pooled analysis, CT significantly improved PFS1, PFS2, and OS. The improvement in PFS2 suggests that the benefit reported during first remission is not cancelled by a shorter second remission. PFS2 is a valuable end point to estimate long-term clinical benefit and should be included in future trials.

Autologous transplantation and maintenance therapy in multiple myeloma.

BACKGROUND: This open-label, randomized, phase 3 study compared melphalan at a dose of 200 mg per square meter of body-surface area plus autologous stem-cell transplantation with melphalan-prednisone-lenalidomide (MPR) and compared lenalidomide maintenance therapy with no maintenance therapy in patients with newly diagnosed multiple myeloma. METHODS: We randomly assigned 273 patients 65 years of age or younger to high-dose melphalan plus stem-cell transplantation or MPR consolidation therapy after induction, and 251 patients to lenalidomide maintenance therapy or no maintenance therapy. The primary end point was progression-free survival. RESULTS: The median follow-up period was 51.2 months. Both progression-free and overall survival were significantly longer with high-dose melphalan plus stem-cell transplantation than with MPR (median progression-free survival, 43.0 months vs. 22.4 months; hazard ratio for progression or death, 0.44; 95% confidence interval [CI], 0.32 to 0.61; P<0.001; and 4-year overall survival, 81.6% vs. 65.3%; hazard ratio for death, 0.55; 95% CI, 0.32 to 0.93; P=0.02). Median progression-free survival was significantly longer with lenalidomide maintenance than with no maintenance (41.9 months vs. 21.6 months; hazard ratio for progression or death, 0.47; 95% CI, 0.33 to 0.65; P<0.001), but 3-year overall survival was not significantly prolonged (88.0% vs. 79.2%; hazard ratio for death, 0.64; 95% CI, 0.36 to 1.15; P=0.14). Grade 3 or 4 neutropenia was significantly more frequent with high-dose melphalan than with MPR (94.3% vs. 51.5%), as were gastrointestinal adverse events (18.4% vs. 0%) and infections (16.3% vs. 0.8%); neutropenia and dermatologic toxic effects were more frequent with lenalidomide maintenance than with no maintenance (23.3% vs. 0% and 4.3% vs. 0%, respectively). CONCLUSIONS: Consolidation therapy with high-dose melphalan plus stem-cell transplantation, as compared with MPR, significantly prolonged progression-free and overall survival among patients with multiple myeloma who were 65 years of age or younger. Lenalidomide maintenance, as compared with no maintenance, significantly prolonged progression-free survival. (Funded by Celgene; ClinicalTrials.gov number, NCT00551928.).

Bortezomib, melphalan, prednisone (VMP) versus melphalan, prednisone, thalidomide (MPT) in elderly newly diagnosed multiple myeloma patients: A retrospective case-matched study.

Novel agents in combination with melphalan and prednisone (MP) significantly improved progression-free survival (PFS) and overall survival (OS) in multiple myeloma (MM). Randomized trials comparing MP plus bortezomib (VMP) versus MP plus thalidomide (MPT) are lacking. Nine hundred and fifty-six elderly (>65 years) newly diagnosed MM patients from six European randomized trials were retrospectively analyzed and matched for age, albumin, and beta2-microglobulin at diagnosis, 296 patients were selected from the VMP groups, and 294 from MPT. Complete response rate was 21% in the VMP patients and 13% in the MPT patients (P = 0.007). After a median follow-up of 34 months (range, 1-92), VMP significantly prolonged both PFS (median 32.5 vs. 22.9 months, HR 0.65; 95% CI 0.52-0.82; P < 0.001) and OS (median 79.7 vs. 45.1 months, HR 0.44; 95% CI 0.32-0.59; P < 0.001) in comparison with MPT. The benefit in terms of OS of the VMP group was quite similar among patients with different risk factors defined by sex, ISS, ECOG performance status, or serum creatinine but not among patients ≥ 75 years. Multivariate analysis confirmed that VMP was an independent predictor of longer PFS and OS. In a control-case matched analysis, PFS and OS were prolonged in patients who received VMP in comparison with those treated with MPT.

Optimal management of elderly patients with myeloma.

Many advances have been made in the treatment of patients with multiple myeloma including elderly subjects. The introduction of novel agents, such as thalidomide, lenalidomide, bortezomib, have revolutionized the treatment paradigm of this neoplasm, and second-generation molecules are currently being tested to offer patients a wider variety of treatment options and to improve outcome. The efficacy of a regimen should be carefully balanced against its toxicity profile. Elderly patients are particularly susceptible to adverse events that may lead to early treatment discontinuation. Thus, a more accurate distinction within the elderly population and a more appropriate treatment allocation is necessary. Here we describe the major and more recent treatment options available today for elderly patients with multiple myeloma.

Role of consolidation/maintenance therapy in multiple myeloma.

Multiple myeloma is a highly treatable but still incurable malignancy. Many advances have been made in the treatment of this disease, particularly thanks to the introduction of the immunomodulatory drugs, thalidomide and lenalidomide, and the proteasome inhibitor, bortezomib. Different trials have supported the inclusion of consolidation/maintenance therapy as part of a sequential approach after induction therapy and transplantation (for eligible patients). This therapeutic strategy aims to maintain or even improve response obtained after induction, and ultimately to prolong survival. The role of consolidation/maintenance therapy has been assessed in patients eligible and ineligible for transplantation, and proved to be a valuable option. The improved outcome reported with consolidation/maintenance therapy should, however, be balanced against the toxicity profile of such an approach. Prolonged exposure to a drug might in fact increase toxicity, and prompt management of adverse events is necessary.

Initial treatment of nontransplant patients with multiple myeloma.

During the last two decades, many steps forward have been made in the treatment of multiple myeloma (MM) thanks to the introduction of the novel agents thalidomide, lenalidomide, and bortezomib. Despite this, MM remains an incurable disease. Elderly patients (≥65 years) represent the majority of subjects. Differently from younger (<65 years) and fit patients, elderly patients are usually not eligible for transplantation. Gentler approaches with novel agents plus conventional chemotherapy with melphalan-prednisone are commonly adopted in this setting. Data show that a sequential approach including induction followed by consolidation/maintenance therapy is an optimal strategy to improve patient outcome. In addition, second-generation novel agents are currently under investigation and may represent valuable alternative treatment options in the future.

The mechanism of action, pharmacokinetics, and clinical efficacy of carfilzomib for the treatment of multiple myeloma.

INTRODUCTION: The development of novel agents, such as immunomodulatory drugs and proteasome inhibitors, has led to a considerable increment in the response rate (RR) and outcomes for multiple myeloma (MM) patients. Unfortunately, MM patients will inevitably relapse and become resistant to new drugs. This led to the continuous development of novel agents. Carfilzomib is a second-generation proteasome inhibitor, demonstrating promising results in relapsed/refractory (RR) and newly diagnosed (ND) MM patients. AREAS COVERED: Herein, the authors review Phase I and II trials on carfilzomib for the treatment of MM. They also describe the profile of the drug during Phase I escalating doses and evaluate the efficacy of carfilzomib both alone and in combination. Finally, the authors also review and discuss the carfilzomib safety profile. EXPERT OPINION: Clinical trials (Phases I and II) with carfilzomib, used both as single agent or in combination with other therapies, established the maximum tolerated dose and recommended schedule of administration. Preliminary data showed that it had a high efficacy and a good safety profile both in RRMM and NDMM patients. Carfilzomib seems to be effective in patients previously treated with bortezomib. Future Phase II and III studies will better define the role of carfilzomib in the treatment of MM as well as its optimum dose.

Diagnosis and therapy of multiple myeloma.

Many advances in the treatment of multiple myeloma have been made due to the use of transplantation and the introduction of novel agents including thalidomide, lenalidomide, and bortezomib. The first step is recognizing the symptoms and starting prompt treatment. Different strategies should be selected for young and elderly subjects. Young patients are commonly eligible for transplantation, which is now considered the standard approach for this setting, and various inductions therapies containing novel agents are available before transplantation. Elderly patients are usually not eligible for transplantation, and gentler approaches with new drugs combinations are used for their treatment.

Age and organ damage correlate with poor survival in myeloma patients: meta-analysis of 1435 individual patient data from 4 randomized trials.

Thalidomide and bortezomib are extensively used to treat elderly myeloma patients. In these patients, treatment-related side effects are frequent and full drug doses difficult to tolerate. We retrospectively analyzed data from 1435 elderly patients enrolled in 4 European phase III trials including thalidomide and/or bortezomib. After a median follow up of 33 months (95%CI: 10-56 months), 513 of 1435 patients (36%) died; median overall survival was 50 months (95%CI: 46-60 months). The risk of death was increased in patients aged 75 years or over (HR 1.44, 95%CI: 1.20-1.72; P<0.001), in patients with renal failure (HR 2.02, 95%CI: 1.51-2.70; P<0.001), in those who experienced grade 3-4 infections, cardiac or gastrointestinal adverse events during treatment (HR 2.53, 95%CI: 1.75-3.64; P<0.001) and in those who required drug discontinuation due to adverse events (HR 1.67, 95%CI; 1.12-2.51; P=0.01). This increased risk was restricted to the first six months after occurrence of adverse events or drug discontinuation and declined over time. More intensive approaches, such as the combination of bortezomib-thalidomide, negatively affected outcome. Bortezomib-based combinations may overcome the negative impact of renal failure. Age 75 years or over or renal failure at presentation, occurrence of infections, cardiac or gastrointestinal adverse events negatively affected survival. A detailed geriatric assessment, organ evaluation and less intense individualized approaches are suggested in elderly unfit subjects.

Evaluation of the pharmacokinetics, preclinical, and clinical efficacy of lenalidomide for the treatment of multiple myeloma.

INTRODUCTION: Lenalidomide is an oral immunomodulatory drug, which was recently introduced for the treatment of multiple myeloma (MM). It has been used for the treatment of newly diagnosed and relapsed MM patients, as both maintenance and preventive therapy. Available data show a progression-free survival and overall survival improvement associated with this drug. AREAS COVERED: Efficacy results of lenalidomide in Phase I, II, and III trials in MM are reported herein. The recent use of lenalidomide as maintenance and preventive therapy is described. An overview of the most important adverse events is also presented, such as myelosuppression, thromboembolic events, fatigue, dermatologic toxicity, infections, teratogenic potential, and second primary malignancies. The literature reviewed consists of clinical trials published from 2001 to 2012. EXPERT OPINION: Lenalidomide is one of the most important therapeutic agents for MM treatment. Various trials have confirmed its remarkable anticancer activity, alone or combined with high- or low-dose dexamethasone, or other drugs. Lenalidomide-related adverse events can be controlled with dose reductions, supportive therapy, and appropriate prophylaxis.